There have been many proposals for the application of liquid contact herbicides to undesirable plants, especially in fields with growing crops and in gardens, to effect destruction of the unwanted plants while not harming the crop plants. Many contact herbicides that are applied, such as ROUNDUP, are extremely potent and effective, and expensive, so that it is desirable to apply only a predetermined small amount of herbicide to plants to be destroyed, and positively prevent application to the crop plants.
Typically, herbicide application in fields with growing plants have been accomplished utilizing recirculating sprayers or wick applicators. Recirculating sprayers do not lend themselves to small area applications, and are extremely complicated, and cannot be utilized effectively under all environmental and field conditions (e.g., when it is extremely windy). Wick applicators have met with a great deal of commercial success and are generally useful, however, they too do not lend themselves to small area applications, and additionally, there can be excessive loss of herbicide (e.g., ROUNDUP) due to evaporation while the applicator is in transit or between uses, and additionally the constantly exposed wick applicator can prevent certain health and safety problems.
According to the present invention, a method of herbicide application, and a particular liquid applicator device eminently suited for such herbicide application, are provided which eliminate many of the drawbacks present in prior art devices, and are especially suited for small area application. The liquid applicator device according to the present invention effectively dispenses a metered amount of herbicide onto plants that are desirably destroyed, and can readily be operated to be self-contained so that no significant evaporation loss of herbicide, and no significant adverse health and safety problems, are presented thereby. The invention facilitates simple yet effective destruction (i.e., killing or substantially reducing the competitive abilities of) undesired plants in fields and gardens where crops are growing.
According to the present invention, a liquid applicator device is provided that is eminently suited for herbicide application (although it may also have other uses). The liquid applicator device includes an elongated container having first and second portions separated by a metering valve, the first portion containing a supply of liquid (e.g., herbicide) and the second portion for receiving metered amounts of the liquid from the first portion. The device also includes an elongated roller having fibrous covering means for receiving liquid from the container and for ultimately transferring the liquid to another object, and having a cross-sectional area, including the covering means, smaller than the inside cross-sectional area of the container second portion. The roller includes a handle extending from one end thereof and valve operating means operatively connected to the other end thereof. The device further comprises a valve actuator means operatively associated with the valve disposed between the container first and second portions, for engagement with the valve operating means, so that movement of the roller relative to at least one portion of the container results in actuation of the valve to meter liquid from the first portion of the container to the second portion thereof.
Preferably the container first and second portions are separable distinct containers, each including means for releasably attaching it to the other container, so that the first container may be removed from the second container and replaced with a new liquid-filled other first container. The valve preferably is a rotary valve, and the roller is preferably a conventional paint roller only having a telescopic rod means interconnecting the handle and a support for the covering means. A number of wiping ridges may be provided on the interior of the second container to facilitate even distribution of the liquid onto the roller covering means.
The valve associated with the device according to the invention preferably comprises a valve housing connected to the first container, the valve housing having an inlet port disposed within the volume defined by the first container and an outlet port disposed on the opposite side of the inlet port, and exteriorly of the volume defined by the first container. The valve further comprises a valve element mounted for rotation in the valve housing, the valve element having a cavity with a predetermined volume formed therein, the cavity effectively extending a length at least as great the longitudinal distance between the inlet and outlet ports of the valve housing, and having a distal portion extending exteriorly of the first container and comprising the valve actuator means. The valve actuator means comprises a key cavity formed in the valve element, while the valve operating means comprises a key corresponding to the key cavity and extending from the roller.
According to the present invention a method of destroying plants is provided that utilizes the liquid applicator device described above. The method comprises the steps of: Effecting the relative movement between the roller and at least one of the first and second portions of the container, to meter a predetermined amount of herbicide from the container first portion to the container second portion, with the roller in place in the second portion to dispose herbicide on the roller covering means. Removing the roller, with herbicide thereon, from the container second portion. Touching the roller to plants that are desirably destroyed, so that herbicide is transferred from the roller to the plants to thereby result in destruction of the plants touched thereby. Reinserting the roller into the container second portion; and occasionally repeating the above steps until desired plant destruction is completed. Whenever the first container is emptied of herbicide, a full container is added. Since the containers are completely separate and distinct and are readily detachable from each other, there will be no significant amount of herbicide that will be wasted, the herbicide with which the device is utilized may be readily changed, and the rates of application of herbicide (metering) may be readily changed by providing different first containers having different valve actuators (for metering different amounts of liquid per activating movement). Preferably the metering of herbicide from one container to the other is accomplished by effecting relative rotational movement between the roller and the first and second containers, and preferably the metering valve is designed so that 360.degree. relative rotation between the roller and the container must be effected a plurality of times to meter the predetermined amount of herbicide from the first container to the second container to facilitate practical practicing of the "touching" step.
It is the primary object of the present invention to provide a simple and effective liquid applicator device, and a method of utilization thereof for destroying plants. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.